The individual steps or pallets on an escalator or moving walkway are removably secured to the step chain axles for each step. The steps can thus be disengaged from the step chain axles for service and maintenance of the escalator. Various step-axle fastening assemblies are disclosed in U.S. Pat. Nos. 2,033,308, granted Mar. 10, 1936 to H. W. Shonnard, and 2,114,805, granted Apr. 19, 1938 to S. G. Margles et al; Document No. SU 1067-165, published on Dec. 23, 1983; and Japanese Patent Application No. 64-111719, published Dec. 3, 1990.
U.S. Pat. No. 3,789,972, granted Feb. 5, 1974 to J. K. Kraft, discloses an escalator step-axle fastening assembly which includes a clamp that is pivotally mounted on the step and that ideally automatically swings into clamping engagement with the step chain axle when the latter is moved into supporting engagement with the step. The pivoting clamp is secured in place by a bolt which is threaded into the step and which is manipulated by a tool such as an Allen wrench inserted through an opening in the step tread. In practice, the pivoting clamp will often jam against the step chain axle as the latter is swung into position beneath the step, thereby necessitating that the step be lifted upward by the installer or serviceman to clear the axle for further movement. Two other problems have surfaced relating to the patented system. The first problem relates to the securement bolt becoming disengaged from the step and falling into the escalator after the step has been uncoupled from the axle. The other problem relates to the difficulty of properly engaging the tool with the bolt through the small opening in the tread.